College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 151-742, Republic of Korea.
School of Pharmacy, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon 440-746, Republic of Korea.
Biochem Pharmacol. 2014 Aug 15;90(4):414-24. doi: 10.1016/j.bcp.2014.06.013. Epub 2014 Jun 21.
Collaborative regulation of liver X receptor (LXR) and sterol regulatory element binding protein (SREBP)-1 are main determinants in hepatic steatosis, as shown in both animal models and human patients. Recent studies indicate that selective intervention of overly functional LXRα in the liver shows promise in treatment of fatty liver disease. In the present study, we evaluated the effects of meso-dihydroguaiaretic acid (MDGA) on LXRα activation and its ability to attenuate fatty liver in mice. MDGA inhibited activation of the LXRα ligand-binding domain by competitively binding to the pocket for agonist T0901317 and decreased the luciferase activity in LXRE-tk-Luc-transfected cells. MDGA significantly attenuated hepatic neutral lipid accumulation in T0901317- and high fat diet (HFD)-induced fatty liver. The effect of MDGA was so potent that treatment with 1mg/kg for 2 weeks completely reversed the lipid accumulation induced by HFD feeding. MDGA reduced the expression of LXRα co-activator protein RIP140 and LXRα target gene products associated with lipogenesis in HFD-fed mice. These results demonstrate that MDGA has the potential to attenuate nonalcoholic steatosis mediated by selective inhibition of LXRα in the liver in mice.
肝 X 受体 (LXR) 和固醇调节元件结合蛋白 (SREBP)-1 的协同调节是肝脂肪变性的主要决定因素,这在动物模型和人类患者中均有体现。最近的研究表明,选择性干预肝脏中超功能的 LXRα 在治疗脂肪肝方面具有潜力。在本研究中,我们评估了间二氢愈创木酸 (MDGA) 对 LXRα 激活及其减轻小鼠脂肪肝能力的影响。MDGA 通过与激动剂 T0901317 的结合口袋竞争性结合,抑制 LXRα 配体结合域的激活,并降低 LXRE-tk-Luc 转染细胞中的荧光素酶活性。MDGA 显著减轻了 T0901317 和高脂肪饮食 (HFD) 诱导的脂肪肝中的肝中性脂质积累。MDGA 的作用非常有效,以致于用 1mg/kg 治疗 2 周即可完全逆转 HFD 喂养引起的脂质积累。MDGA 降低了 RIP140 这种 LXRα 共激活蛋白和与 HFD 喂养小鼠中脂肪生成相关的 LXRα 靶基因产物的表达。这些结果表明,MDGA 具有通过选择性抑制肝脏中的 LXRα 来减轻非酒精性脂肪性肝病的潜力。